JPS61252368A - Method for imparting water and oil repellency to porous hollow yarn - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for imparting water and oil repellency to porous hollow fibers.

[Conventional technology and problems]

Recently, porous hollow fibers made of various materials have been developed and are being applied to various water treatments, artificial organs, etc. as separation membranes for removing fine substances.

These porous hollow fibers have a much larger surface area than flat membranes, so they have excellent filtration efficiency. Hydrophobic polymers such as polymers are used. When separating water and aqueous liquids, hydrophilic porous hollow fibers whose surfaces are easily wetted by water are suitable, but the latter porous hollow fibers made of hydrophobic materials require hydrophilic treatment. Various hydrophilic treatment methods have been proposed as necessary.

On the other hand, when blood gas exchange is performed through porous hollow fibers as in an artificial lung, hydrophilic hollow fibers are not preferred because liquids such as blood may enter the hollow fibers.

On the other hand, the surface of hydrophobic porous hollow fibers is not wetted by liquids such as blood, so liquids do not penetrate into the pores, making them suitable for use in oxygenators as membranes. However, when an oxygenator module using hydrophobic hollow fibers is used for a long time, oily substances with surfactant properties such as phospholipids contained in blood adhere to the hollow fiber walls and penetrate into the laminated structure. Since a molecular film is formed, the surface of the hollow fiber becomes hydrophilic, causing a problem of blood leakage.

One possible solution to this problem is to use porous hollow fibers coated with a fluoropolymer that has excellent water and oil repellency, but since the entire hollow fiber has high water and oil repellency, When air bubbles are introduced, the air bubbles tend to aggregate and grow, and the energy required to separate the air bubbles from the surface of the hollow fiber increases, making it difficult to remove the air bubbles from the surface.

Therefore, the surface that comes into contact with gas has high water and oil repellency,
It is desired that the surface of the porous hollow fiber that comes into contact with liquid such as blood has weaker hydrophobicity.

[Means for solving problems]

The above problem is that the micropores communicate with the inner and outer wall surfaces of the hollow fibers, and the water and oil repellent agent A; the solvent B that dissolves the same, and the is brought into contact with an incompatible solvent C, and then a solution of water and oil repellent agent A dissolved in solvent B is brought into contact with another wall surface that is not in contact with solvent C to penetrate into the inside of the laminated structure of hollow fibers. The present invention relates to a method for imparting water and oil repellency to porous hollow fibers, which comprises subsequently performing a solvent removal treatment to coat only one wall surface of the hollow fibers with a water and oil repellent substance.

Porous hollow fibers in which micropores communicate between the inner and outer wall surfaces of the hollow fibers include polyolefin hollow fibers as previously shown in JP-A-57-42919, as well as acrylonitrile copolymers, cellulose, etc. Hydrophilic hollow fibers are used, but among these, polyolefin hollow fibers with excellent gas exchange ability, chemical stability, mechanical properties, and biocompatibility are used for purposes such as oxygen exchange. is preferred.

Examples of the water-based oil agent A to be used include fluororesins and silicone-based resins, but fluororesins containing perfluoroalkyl chains are preferred in order to obtain excellent water and oil repellency. Furthermore, in the case of a hydrophobic material such as a polyolefin hollow fiber, it is preferable to use a solvent-type water and oil repellent because the material is uniformly coated with the water and oil repellent. Solvent B is preferably a solvent that easily dissolves T8 water and oil repellent A and is highly volatile at room temperature, such as trichloroethane, dichloroethane,
Examples include ethyl acetate, methyl ethyl ketone, tetrahydrofuran, and acetone.

On the other hand, as the solvent C that is brought into contact with either the inner wall surface or the outer wall surface of the porous hollow fiber, any solvent that is incompatible with the water and oil repellent agent A and the solvent B that dissolves it can be used. However, depending on the purpose, a material with excellent safety and volatility is preferable, and water or a mixed solution of water and ethanol is suitable.

As a method of bringing the solvent C into contact with the inner or outer wall surface of the porous hollow fibers, for example, after bundling the porous hollow fibers and fixing both ends with a potting material, the solvent C is uniformly applied to the inner or outer wall surface of the hollow fibers. Fill to make contact. In this case, it is not preferable that the solvent C easily pass through the porous wall of the hollow fiber, and it is important to select a solvent that does not easily pass through when brought into contact with the hollow AI material.

A method of coating the wall surface of the hollow fiber that is not in contact with solvent C with a water- and oil-repellent substance is to prepare a solution of water- and oil-repellent agent A dissolved in solvent B to a predetermined concentration and coat it on the outer wall surface. In this case, the hollow fibers are filled with solvent C and then immersed in T8 water and oil repellent for a predetermined period of time, then pulled out to sufficiently evaporate and dry the solvent B, and then the solvent C filled inside the hollow fibers is extracted. .

In addition, when coating the inner wall surface of the hollow fiber with a water and oil repellent, apply solvent C to the outer wall surface of the hollow fiber, and after passing a water and oil repellent solution of a predetermined concentration over the inner wall surface of the hollow fiber in a state in which it is in uniform contact with the inner wall surface of the hollow fiber. It can be obtained by evaporating and drying the solvent B, but when passing the water and oil repellent solution through the hollow fibers, an aspirator is used.
A method of suctioning a predetermined amount of the water/oil repellent solution from the other end using a vacuum cleaner or the like is preferable in order to uniformly treat the water/oil repellent material. The concentration of the water and oil repellent is preferably in the range of 0.65 to 30% by weight; if it is less than 0.5% by weight, sufficient water and oil repellency cannot be obtained, and if it is more than 30% by weight, the water and oil repellent is This is because the porous layer is often clogged with resin.

The thus obtained water- and oil-repellent porous hollow fibers have excellent water- and oil-repellent performance because either the outer wall surface or the inner wall surface is coated with a water-repellent 1Ω oil-based substance. ,
Particularly when blood gas exchange is performed through hollow fibers, such as in an artificial lung, the adhesion and penetration of hydrophilic substances contained in the blood into the interior of the laminated structure must be suppressed by water- and oil-repellent substances on the gas side. becomes possible. Moreover, the other wall surfaces are made of hollow fiber material and have the original properties, so it can be used for a variety of purposes.

The present invention will be explained below with reference to Examples.

〔Example〕

Using a module with a length of 10, which is made by bundling 400 large carbonized polypropylene porous hollow fibers KPF (Mitsubishi Rayon) and fixing both ends with urethane potting material, the module is filled with pure water, and the hollow fibers are Pure water was brought into sufficient contact with the outer wall surface of the

Next, a solvent solution dissolved in 30 parts by weight of fluorine-based water and oil repellent DickGuard F-320 (Dainippon Ink Chemical) and 70 parts by weight of trichloroethane was sucked into the hollow fibers from the lower end of the module to the upper end of the module at room temperature. Trichloroethane was evaporated after contacting the wall and passing through the outer wall.

The pure water that had been in contact with the module was removed and sufficiently dried in a vacuum dryer to obtain a water- and oil-repellent porous hollow fiber in which the inner wall surface of the porous hollow fiber was coated with a water- and oil-repellent substance.

A mini-module was made using this water- and oil-repellent porous hollow fiber, and 10 cc of lecithin solution was mixed with 50 cc of lecithin solution (2% by weight of lecithin dissolved in ethanol) and the same amount of water.
The mini module was immersed for a minute to forcibly adhere the hydrophilic substance to the mini module, and then sufficiently dried again in a vacuum dryer. Subsequently, we measured the water pressure resistance of this mini module and found that it was 1.5 kg f /ci, indicating that when water- and oil-repellent porous hollow fibers were used, the adhesion and penetration of lecithin, a hydrophilic substance, was less likely to occur. It became clear that there was.

Next, after soaking the module in ethanol to make it sufficiently hydrophilic, the water flux was measured and it was 0.9 cc/
el+!・min ・(kg/cd), and 1
It was confirmed that no porous clogging occurred due to the coating with the 8 water oil repellent.

A module made by bundling 400 polyethylene porous hollow fibers EHF-270T (Mitsubishi Rayon) is filled with pure water, and after uniformly contacting the inner wall surface of the hollow fibers, the fluorine Thread water and oil repellent Asahi Guard AG-650 (
Meisei Chemical) was immersed in a solution of 25 parts by weight dissolved in 75 parts by weight of trichloroethane for 30 seconds and pulled up to evaporate the trichloroethane at room temperature. After coating the outer wall of the hollow fiber with a water- and oil-repellent substance, it was filled inside the hollow fiber. the water that had been
It was thoroughly dried using a sampling vacuum dryer.

Example 1 using the above water- and oil-repellent module
After the hydrophilic substance was forcibly attached in the same manner as in 1-, sufficient drying was performed again using the vacuum dryer.

I subsequently measured the water pressure resistance of this module and found it to be 1.6.
kg f /ruJ. Furthermore, water flux measurements and surface observation using an electron microscope confirmed that the pores were not clogged.

Comparison ±1 A module was fabricated in the same manner as in Example 1 except that no water/oil repellent treatment was applied, and the water pressure resistance was measured.
Q, 8cc/al-win・(kg
/cd), and the water-repellent TA-oil agent coated module of Example 1 had the same level of properties as this, which revealed that there was no influence from the 18 water-oil repellent treatment.

A module was fabricated in the same manner as in Example 2, except that it was not treated with water, water, oil, or oil. When the water pressure resistance was measured, it was as low as 0°8 kgf/cs. When the water flux was measured after being immersed to make it sufficiently hydrophilic, it was 0.8 cc/cla-in.
・(kg/cj), and the water-repellent tn oil coated module of Example 2 is about the same level, so
It became clear that the water-repellent F8 oil treatment had no effect.

〔Effect of the invention〕

The water- and oil-repellent porous hollow fibers of the present invention whose inner or outer wall surfaces are coated with a Ta-water-water-oil-based substance have excellent water- and oil-repellency. This makes it possible to suppress the adhesion and intrusion of hydrophilic substances in the blood that occur when gas exchange is carried out through Even if air bubbles are attached due to this, they can be easily peeled off from the hollow system, making it easy to remove air bubbles from the blood, and (θ water loss) is safe because the oily substance has low hemolytic properties.

Claims (1)

[Claims] 1. Water and oil repellent A and the water and oil repellent agent A are dissolved in one of the inner and outer wall surfaces of the hollow fiber where the micropores communicate with the inner and outer wall surfaces of the hollow fiber. Solvent C, which is incompatible with Solvent B, is brought into contact, and then a solution of water and oil repellent A dissolved in Solvent B is brought into contact with the other wall surface that is not in contact with Solvent C to form a laminated structure of hollow fibers. A method for imparting water and oil repellency to porous hollow fibers, the method comprising coating only one wall surface of the hollow fibers with a water and oil repellent substance by allowing the material to penetrate inside and then performing a solvent removal treatment. 2. The method according to claim 1, wherein the porous hollow fibers are made of a polyolefin polymer. 3. The method according to claim 1, wherein the water and oil repellent A is a fluororesin.